As is well known, it is often desirable within the art fields of medicine, pharmacy, chemistry and the like, to require the transfer of fluids from a separated source thereof to a delivery location. This is especially true in the medical arts where often, it is necessary or desirable to transfer fluids such as blood, parenteral solutions, and the like from a stored container to either a different container, or for direct patient usage. In most instances, the separated fluid source comprises a container and is manufactured with conduit means associated with the container and extending outwardly therefrom. In order to effect the transfer from the container to a patient or to a different container, it is necessary to have a connector which will establish a fluid flow path from the storage container to the other container or the patient. It will also be appreciated that where sterility is required, such connectors must be sterile at the inception, and must maintain a sterile environment for the fluid passing therethrough.
One of the primary difficulties in designing suitable sterile connectors is the fact that the danger of contamination from air borne materials as well as other contaminants in and around the environment surrounding the point of delivery may easily find their way into the interior portion of the present connectors. Hence, the provision of a sterile connector which may be easily manipulated by the operator to establish an assured sterile fluid flow.
It has been determined that the fabrication of a sterile connector for joining a supply source to an independent delivery location through a contaminated environment requires at least four important design steps:
1. The alignment of the connector housings;
2. Excluding of the contaminated environment;
3. Sterilization of the excluded region;
4. Penetration within the sterilized area followed by coupling of the protected internal conduits.
Due to the above noted design parameters, it has usually been necessary to design sterile connectors which are not only rigid in construction, but are rather cumbersome to use, and also require various forms of mechanical means to join the two connector bodies together in a sterile and fluid tight sealing arrangement such that a sterile environment is retained within the common collection chambers established between the two joined faces of the connector bodies.
Exemplary of the most recent developments in this particular art field is shown in U.S. Pat. No. 3,865,411 which is directed to a sterile connector for interconnecting opposed separated conduits. As exemplified by the above noted patent, the sterile connector is formed by a flanged body portion carried at the end of an appropriate conduit, and further includes a compressible gasket made from an elastomeric material. A diaphragm or pull tab cover is positioned over the adjoining face of the compressible gasket and which includes a long fold extending laterally outwardly from adjoined faces of the corresponding gasketed portions of the connector. It will further be appreciated that once the joined faces are brought together, the two gasketed portions must be clamped together by some mechanical means such as a spring-loaded clamp or snap fitting bale arrangement in order to compress the gaskets together, and maintain a seal while simultaneously removing the pull tab covers between the two faces so that a fluid flow path is established between the opposed conduits. Hence, it will be appreciated that the sterile connector actually includes two elements, including a sterile internal connector proper, and a housing serving as an environmental barrier. It will be appreciated that in such a system, contamination from the environment theoretically occurs upon removal of the housing preliminary to joining the sterile internal elements. It is for this reason that devices such as pull tab covers, which are designed to be removed upon the commencement of the joining of the two connector body members, have been designed such that once the connector housings are in proper alignment and the joining commences, the pull tab covers may be removed to establish the fluid flow path under sterile conditions.
Another system incorporated in sterile connector members has been the use of a loop of nichrome wire which is substituted for any type of mechanical penetrator. In systems of this type, the openings establishing the common chamber are usually covered with a membrane of some type and having a looped nichrome wire positioned immediately beneath one of the membranes. Once the joining faces are brought together, the loop is energized by an external voltage source, thereby to heat the wire in order to penetrate through the membranes and establish a fluid flow path. Additionally, the energizing of the nichrome wire loop functions to sterilize the immediate environment in the fluid path.
It will be appreciated from the above discussion that various difficulties have been encountered in connection with sterile connectors. For example, in many applications, such as the preparation of frozen blood, the blood is provided in flexible containers which are then placed in facilities in order to effect the freezing of the blood. In practice, such containers will assume a very thin configuration, as a package to facilitate heat transfer and freezing. The connectors must be dimensionally suited for inclusion in such a "thin" package configuration.
Even more importantly, it has been deemed desirable to provide a sterile connector concept which lends itself to thin, flexible applications, as well as to conceptionally provide a connector which is adaptable to interconnect multiple fluid sources but in a simplified manner.